Thanks on being fed last of the drink (3)
I believe the answer is:
tea
'drink' is the definition.
(tea is a drink)
'thanks on being fed last of the' is the wordplay.
'thanks' becomes 'ta' (UK informal version of 'thank you').
'on being fed' means one lot of letters goes inside another.
'last of' says to take the final letters.
The last letter of 'the' is 'e'.
'ta' going around 'e' is 'TEA'.
(Other definitions for tea that I've seen before include "tips for the cup?" , "Hot drink" , "Eg, gunpowder, pekoe" , "Assam, e.g." , "Beverage from leaves" .)